Abstract:
The results from three year’S continuous experimental study on the alfalfas of introductory varieties show that the alfalfa varieties with fall-dormancy grades 2~5 are suitable to be cultivated in north of North-China Plain,meanwhile some counterm easures must he taken to enhance the survival rate in winter;the varieties with falbdormancy grades 6 and 7 can not be spread out;the three varieties Haygarzer,Vector and Key can be harvested from 4 to 5 crops annually,and are suitable to be cultivated in Bering area;the alfalfas survive safely in summer in Beijing area,but some prevention measures must be taken to resist plant diseases and insect pest;the relation between the output and accumulative temperature of alfalfa is linear in that sowing year,and logarithmic in the following years.